1. Field of the Invention
This invention relates generally to vehicle air conditioning refrigeration circuits, and specifically to an improved refrigerant reservoir for use in said systems.
2. Description of the Prior Art
A typical vehicle refrigeration circuit comprises a compressor, a condenser, an expansion valve/orifice tube or refrigerant metering device, and an evaporator as principal components. Refrigerant is circulated through the circuit to produce cooling. Energy is provided to the circuit by the compressor which is driven by the vehicle engine, and which serves to create a source of high pressure gas refrigerant which is allowed to pass through the condenser where the refrigerant dissipates heat and changes state to a high pressure liquid. The refrigerant then passes through the expansion valve and into the evaporator changing state from high pressure liquid, to low pressure liquid, and subsequently to low pressure gas, thereby removing heat from the vehicles passenger compartment and with the aid of a blower motor creates a cooling effect inside the vehicle. From the evaporator the refrigerant is then drawn back to the compressor in a low pressure gas form, where it is again compressed into high pressure gas for repetition of the cycle.
An accumulator is an additional typical refrigeration circuit component normally coupled between the evaporator and the compressor, and serving as a protective device for the compressor by separating liquid refrigerant from vaporous refrigerant, since it is undesirable to pass liquid refrigerant to the compressor. Additionally, an accumulator functions to remove moisture which may be mixed with refrigerant in the refrigeration circuit. Usually, a desiccant assembly is provided in the interior of the accumulator to absorb moisture.
The function of an accumulator is well established in refrigerant systems. Essentially, it consists of a device for modifying the flow of refrigerant in the system and for preventing liquid refrigerant from reaching the compressor. In operation, refrigerant is directed against the inner wall of the container and is caused to circulate about the inner periphery. In so doing, the velocity of the refrigerant is reduced to a great extent and any liquid contained in the refrigerant, be it liquid refrigerant, oil, or water, is encouraged to cling to the side wall and drain to the lower portion of the container, while vaporous refrigerant is accumulated in the upper portion of the container.
In many conventional accumulators, vaporous refrigerant is removed from the upper portion of the container by a u-shaped or j-shaped tubular conduit, having an opening at the upper end of the container and being routed through the lower end, further having a metering orifice at the lower end for controlled pick-up or reentry of liquid, particularly oil, to the flow of refrigerant, since it is also desirable that oil be maintained in the vapor flow to the compressor for lubrication.
With the advent of down-sized vehicles, the available space in vehicle engine compartments has been reduced such that clearance for air conditioning components and their required plumbing connections has necessitated separate plumbing arrangements for each model. Such separate plumbing arrangements have greatly complicated the installation and repair of vehicle air conditioning systems, and increased the cost of such systems.
In addition, it is often also necessary for the inlet and outlet of the accumulator to be in a particular geometric relationship to the refrigerant reservoir so that refrigerant lines can be connected to them. Thus, a variety of accumulators must be manufactured to satisfy the requirements of the plurality of vehicle types on the market or in current use.